Access device for accessing tissue

ABSTRACT

A clip is provided for managing access through tissue. The clip is placed around an opening in tissue, although the opening may alternatively be formed after the clip is deployed. The clip can expand when medical devices are introduced through the clip and through the opening. When the medical devices are removed, the clip closed automatically to substantially close the opening.

BACKGROUND

1. The Field of the Invention

Embodiments of the invention relate generally to medical devices. Moreparticularly, embodiments of the invention relate to medical devices formanaging access in body tissue and/or body lumens.

2. The Relevant Technology

Catheterization and interventional procedures, such as angioplasty orstenting, are generally performed by inserting a hollow needle through apatient's skin and tissue into the patient's vascular system. A guidewire may be advanced through the needle and into the patient's bloodvessel accessed by the needle. The needle is then removed leaving theguide wire in place, enabling an introducer sheath to be advanced overthe guide wire into the vessel, e.g., in conjunction with or subsequentto a dilator.

A catheter or other device may then be advanced through a lumen of theintroducer sheath and over the guide wire into a position for performinga medical procedure. The introducer sheath may facilitate introducingvarious devices into the vessel, while minimizing trauma to the vesselwall and/or minimizing blood loss during a procedure. As the variousdevices are introduced through the introducer sheath, the opening oraccess site formed in the vessel may be subjected to additional traumaor tearing during the medical procedure.

Upon completing the procedure, the devices and introducer sheath areremoved, leaving a puncture site or opening in the vessel wall.Traditionally, external pressure would be applied to the puncture siteuntil clotting and wound sealing occur; however, the patient must remainbedridden for a substantial period after clotting to ensure closure ofthe wound. This procedure, however, may be time consuming and expensive,requiring as much as an hour of a physician's or nurse's time. It isalso uncomfortable for the patient and requires that the patient remainimmobilized in the operating room, catheter lab, or holding area. Inaddition, the insertion and removal of various medical devices can leadto problems at the access site.

BRIEF SUMMARY

Embodiments of the disclosure relate to managing access to tissue or tobody lumens. Embodiments of the invention relate more particularly to anaccess device that controls access to openings formed in the tissue. Inone embodiment, the access device includes a body having an interioredge and an exterior edge. The access device also includes an engagementmechanism that extends from the body. The engagement mechanism engagesor attaches to the tissue. The body is configured to deform from a firstposition to a second position while the engagement mechanism is engagedwith the tissue. The device may be bi-modal and be configured to holdboth a first position (closed) and a second position (e.g., open)without an external bias.

In another embodiment, the access device manages access to tissue andcan reduce trauma to the opening formed in the tissue. In this example,the access device includes a body. The body includes a first portion anda second portion joined at a fold. The first portion and the secondportion are typically set in a first position and configured to deformto a second position. When deforming to the second position, an interiorof the clip defined by the first and second portions effectivelyenlarges by, for example, elastic deformation to allow medical devicesaccess to the opening. The access device includes a plurality of prongsthat extend from the first and second portions. The first and secondportions engage the tissue around the opening and attach the body to thetissue. The prongs can extend from either an interior or exterior edgeof the access device's body.

In operation, a method for managing tissue often begins by forming anopening in the tissue. An access device is then placed or attached tothe tissue around the opening, although the access device can be placedbefore the opening in the tissue is formed. The access device engagesthe tissue. During the procedure, the access device can be expanded toallow access to the opening. Through the interior of the access device,medical devices can be introduced through the opening. When the medicaldevices are removed, the access device returns to its original positionand, because the access device is attached to the tissue, substantiallycloses the opening in the tissue.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by the practice of the invention. Thefeatures and advantages of the invention may be realized and obtained bymeans of the instruments and combinations particularly pointed out inthe appended claims. These and other features of the present inventionwill become more fully apparent from the following description andappended claims, or may be learned by the practice of the invention asset forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which at least some of the advantagesand features of the invention can be obtained, a more particulardescription of the invention briefly described above will be rendered byreference to specific embodiments thereof, which are illustrated in theappended drawings. Understanding that these drawings depict only typicalembodiments of the invention and are not therefore to be considered tobe limiting of its scope, the invention will be described and explainedwith additional specificity and detail through the use of theaccompanying drawings in which:

FIG. 1 shows an illustrative view of a medical device used to access abody lumen through an opening in a vessel to perform a medicalprocedure;

FIG. 2 shows an illustrative example of an access device that controlsor manages access to a body lumen, such as a blood vessel, through theopening;

FIG. 3 shows an illustrative example of the access device of FIG. 2 inan expanded position to accommodate the introduction of a medical devicethrough the opening in the body lumen;

FIG. 4A shows an illustrative example of an access device in a firstclosed position;

FIG. 4B shows an illustrative example of the clip in a second, expandedor open position;

FIG. 4C shows a side view of the access device in a first, closedposition;

FIG. 4D illustrates an example of the access device where the prongsoriginate from a body of the clip rather than an internal or externaledge of the clip;

FIG. 4E illustrates the access device with a latch configured to holdthe access device in a closed position;

FIG. 5A shows an example of the access device in a first, deployedposition in tissue;

FIG. 5B shows an example of the clip in a second, expanded position toaccommodate introduction of a medical device;

FIG. 6A shows another illustrative example of an access device or clipwith prongs on an outer edge of the access device and in an expanded oropen position;

FIG. 6B shows the access device of FIG. 6A in a contracted or closedposition;

FIG. 7A illustrates an access device or bi-modal clip biased in a closedposition;

FIG. 7B illustrates the bi-modal clip in FIG. 7A in an open and unbiasedposition;

FIG. 8A illustrates another example of a bi-modal clip configured tocontrol access to tissue in a closed position;

FIG. 8B illustrates the bi-modal clip of FIG. 8A tissue in an openposition;

FIG. 9A illustrates a perspective view of another bimodal clip;

FIG. 9B illustrates top view of the bimodal clip shown in FIG. 9A in afirst position;

FIG. 9C illustrates a top view of the bimodal clip shown in FIG. 9A in asecond position;

FIG. 10A illustrates a perspective view of another example of a bimodalclip;

FIG. 10B illustrates a side view of the bimodal clip of FIG. 10A in afirst position;

FIG. 10C illustrates the side view of the bimodal of FIG. 10A in thesecond position; and

FIG. 10D illustrates the side view of the bimodal clip of FIG. 10Atransitioning from the first position to a second position or viceversa.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Embodiments of the invention relate to an access device, such as a clip,used in managing access to and/or through tissue. In many medicalprocedures, it is often necessary to create an opening or an access sitein tissue for various reasons, including to introduce medical devicesinto the tissue or into body lumens. For example, an opening is oftenformed in a body lumen, such as a vessel, by puncturing the vessel.After the opening is formed in the vessel, the same opening is used toaccess the vessel lumen with other medical devices.

Although embodiments of the invention are discussed with reference to avessel, one of skill in the art can appreciate, with the benefit of thepresent disclosure, that embodiments of the invention can also be usedin conjunction with other tissue, lumens, and/or with other procedures.In general, embodiments of the invention relate to methods and devicesfor managing access to body lumens.

Embodiments of the invention relate to an access device (also referredto herein as a clip), that may be placed around the opening formed inthe vessel. In one example, the clip is placed in or on the vesselbefore the opening is formed. In other words, the clip is configured forpre-puncture deployment. In one example, the clip can be configured toclose the puncture at least temporarily in addition to being configuredfor reducing or minimizing trauma to the vessel.

For instance, the clip may reduce or minimize tearing that may occur atthe opening during the insertion and/or removal of medical devices suchas an introducer sheath or for other reasons. Minimizing trauma to thevessel, by way of example only, can improve recovery time, keep the sizeof the opening to a minimum, and make the procedure easier to perform.

The clip typically engages at least some of the tissue surrounding theopening in the tissue. Should a tear in the opening occur, the extent ofthe tear may be minimized because the clip may prevent the tear fromexpanding past the boundaries of the clip. In order to allow the medicalprocedure to be performed, the clip is usually deformable and/orexpandable from a closed position to an expanded position. This enablesadditional or larger medical devices to be introduced. The cliptypically is biased, whether mechanically or materially, i.e. by being ashape memory material, however, and automatically moves toward and/or tothe closed position when possible. Alternatively, the clip may bebi-modal and configured to remain in either an open or closed position.In this example, the clip can transition to either position.

The clip may also be configured to snap to a closed position and snap toan open position. In other words, the clip may be configured to exist inboth the closed position and in the open position without any externalforce. The clip may be formed such that when a force is applied to openthe clip, the clip snaps to the open position. Similarly, the clip maysnap to the closed position as well. In this case, the body of the clipis configured either mechanically and/or materially to bias the clip toboth the open position and the closed position—no external bias isneeded to keep the clip in either the open or closed position. The sidesof the clip may be angled, for instance, and have a point at which theclip snaps to one position or the other position. Forcing the clip, orportion thereof, past the point causes the clip to snap to the otherposition.

In another example, a locking or holding mechanism may be used in atleast some of the embodiments disclosed herein to keep the clip ineither an open position or a closed position. The locking or holdingmechanism can lock or hold the clip in an open position and/or hold theclip in a closed position.

Generally, the clip is configured to keep the opening closed. When amedical device needs to be introduced through the opening, the clip canbe deformed or expanded or opened to allow entry of the medical device.When the medical device is removed, the clip is biased toward itsoriginal form or closed. Often, contraction of the clip can at leastpartially close the opening in the vessel.

The clip includes engagement mechanisms that can engage the vessel wall(or other tissue) around the opening. The engagement mechanisms allowthe clip to be attached to the vessel wall. In some instances, the clipcan also be shaped or contoured to accommodate the shape or contours ofthe body lumen. For example, the clip may be shaped to conform to theouter surface of the lumen. When a medical device (e.g., an introducersheath or catheter) needs to be introduced, the clip can be expanded toenable introduction of the medical device via the opening. When themedical device is withdrawn from the opening, the clip moves toward toits previous shape, closing the opening in the vessel in some examples.Embodiments of the clip or access device disclosed herein may includefeatures from any of the other embodiments or Figures discussed herein.

FIG. 1 shows an illustrative view of a medical device used to access abody lumen, such a blood vessel, through an opening in the body lumen toperform a medical procedure. In FIG. 1, the medical procedure includesforming a puncture or opening 102 in a vessel 100. More specifically, awall of the vessel 100 is punctured with a needle, trocar, or otherdevice 106 attached to a medical device 104. The needle 106 creates theopening 102 in the vessel and the needle 106 is often used to insert aguide wire into a lumen 112 of the vessel 100. Once the needle 106 isremoved (typically leaving the guide wire in place), other medicaldevices can access the lumen 112 of the vessel 100 through the opening102. Medical procedures, such as stenting procedures and the like, areoften performed through the opening 102 in the vessel 100. As theseprocedures are performed, the necessary devices are often introducedinto the patient's vascular or other system through the opening 102 inthe vessel 100.

FIG. 2 shows an illustrative example of a clip 200 that controls ormanages access to the vessel 100 or to the lumen 112 of the vessel 100through the opening 102. The clip 200 can be placed or attached to thevessel 100 before or after the opening 102 is formed in the vessel 100.However, the clip 200 is typically placed before other medical devices(e.g., an introducer sheath) such that the clip 200 can minimizeadditional trauma (e.g., tearing) of the vessel 100 at the opening 102.

FIG. 2 shows the clip 200 anchored or secured to the vessel 100 aroundthe opening 102. The clip 200 may be embedded in or fixed to the wall ofthe vessel 100 or have an engagement mechanism that can attach or affixto the wall of the vessel 100. The attachment or connection between theclip 200 and the vessel 100 can be temporary and the clip 200 can beremoved or repositioned if necessary. However, the clip 200 can remainattached with the wall of the vessel 100 during the procedure or as longas necessary. In some instances, the clip 200 may be formed frombiodegradable or biocompatible material and/or be left in placelong-term.

FIG. 2 also illustrates that the clip 200 and may be shaped such thatthe opening 102 is closed or substantially closed when the clip 200 isinitially deployed. During deployment, the clip 200 may be expandedslightly such that the clip 200 closes the opening 102 once theengagement mechanism engages the walls of the vessel 100. Because theclip 200 is expandable or deformable, the clip 200 can deform toaccommodate other medical devices and enable access through the opening102. However, a second closure mechanism, such as a suture, staple,medical clip, plug, or other closure mechanism, or combinations thereofmay be used.

FIG. 3 shows an illustrative example of the clip 200 in an expandedposition to accommodate the introduction of a medical device 110 throughthe opening 102 in the vessel 100. FIG. 3 shows a medical device 110being used to access the lumen 112 of the vessel 100. Often, the medicaldevice 110 is introduced to the lumen 112 via an introducer sheath 108.When the introducer sheath 108 (or other device) is inserted through theopening 102, the clip 200 expands or deforms to accommodate theintroducer sheath 108.

Because the introducer sheath 108 is typically larger than the needle106 that initially formed the opening 102. The larger size of theintroducer sheath 108 may cause the opening 102 to stretch or expand inorder to accommodate the introducer sheath 108. The clip 200 may be ableto control or at least limit the ultimate size of the opening 102. Forexample, the clip 200 may prevent or limit tearing of the opening 102during a medical procedure or during portions of the medical procedure(e.g., introduction of the introducer sheath 108) and thus help reduceor minimize trauma at the opening 102.

The size of the clip 200 can vary. The clip 200 is typically selectedaccording to the medical devices that are being used for a givenprocedure. The clip 200 should be selected such that when the clip 200is fully expanded, the clip 200 can accommodate the necessary medicaldevices through the clip's interior. In some instances, the clip 200 maybe larger than the medical devices such that the clip 200 does notitself impede the introduction and/or removal of the various medicaldevices. FIG. 3, for example, illustrates a space 302 between the clip200 and the introducer sheath 108.

Once the procedure is finished and the introducer sheath 108 is removed,the clip 200 contracts or moves toward to its original shape asillustrated in FIG. 2. When the clip 200 returns toward its original orun-deformed state or when the clip 200 is actively closed, the opening102 may be closed or substantially closed by the clip 200. In oneembodiment, the clip 200 may serve as a vessel closure device inaddition to providing vessel support during the procedure. In this case,the opening 102 may not require any additional procedures that wouldotherwise be performed to close the opening 102. However, a secondclosure mechanism, such as a suture, staple, medical clip, plug, orother closure mechanism, or combinations thereof may be used.

In one example, the clip 200 is deformed to open the clip as shown inFIG. 3. As a result, the clip 200 naturally closes. Alternatively, theclip may be deformed in order to close the clip 200. The clip 200 may beheld closed, in one example, by a locking mechanism.

FIG. 4A shows an illustrative embodiment of a clip 400, which is anexample of the clip 200, in a closed position shown in a perspectiveview. As previously mentioned, the clip 400 can be deformed such thatdimensions or shape of an interior 410 can be changed. Changing thedimensions of the interior 410 enables medical devices of differentsizes to be accommodated in the interior 410 defined by the clip 400.

The clip 400 may be formed of any material that would bias the cliptoward the closed position or may be formed such that the clip canself-bias in two different positions. For example, the material may haveshape memory. The clip 400 is usually set in the closed position. As theclip 400 is expanded to an expanded position (e.g., to accommodate theintroduction and/or removal of various medical devices), the clip 400moves toward the closed position in the absence of an expanding force.The clip 400 may alternatively be deformable to achieve the closedposition. In deforming the clip in this example, the clip may be movedtowards a locking mechanism to keep the clip 400 in the closed position.

In FIG. 4A, the clip 400 is illustrated as having a body that includes afirst portion 402 joined with a second portion 404. As shown, clip 400may be at least partially folded at a fold 406. FIG. 4A illustrates thatthe portions 402 and 404 are curved and join at the fold 406. In oneembodiment, the portions 402 and 404 are symmetrical, although theportions 402 and 404 can be non-symmetrical. The clip 400 can bedeformed in multiple dimensions as well. For example, the clip 400 canbe flattened. In addition or in the alternative, at least a part of theclip's body may twist or rotate. In addition, a curve 416 of theportions 402 and 406 may be shaped to accommodate a vessel, forinstance. The curve 416 may be, by way of example only, circular,elliptical, or otherwise shaped. Deformation or expansion of the clip400 may change a shape of the curve 416 as well. However, the curve 416can be more flat or curved as well in either the closed or expandedpositions.

The clip 400 may be shaped to accommodate specific tissue and to be usedwith specific openings, such as an opening in a vessel. For example, theclip 400 may be selected according to the body lumen being accessed.Larger clips may be used with larger vessels. In addition, the size ofthe medical devices may have an impact on the size of the clip selectedbecause the medical devices are typically inserted through interior 410defined by the portions 402 and 404 of the clip 400.

The clip 400 may include prongs 408 that extend inwardly from each ofthe first portion 402 and the second portion 404 into the interior 410or in the general direction of the interior 410. During deployment, theclip 400 may be at least partially expanded and placed at the opening inthe vessel such that the prongs 408 engage the tissue (e.g., vesselwall) around the opening. The clip 400 can then be released. As the clip400 returns toward its set shape or closed position, the portions 402and 404 pull the tissue around the opening in a manner that closes or atleast reduces a size of the opening in the vessel. The prongs 408 canengage the tissue around the opening and tearing of the opening can bereduced during a procedure as the clip 400 can constrain the medicaldevice used during the procedure. In addition, at least a portion of anyforce exerted by the medical devices on the vessel wall may at leastpartially be borne by the clip 400 rather than solely by the vesselwall. As a result, the vessel is less likely to tear during the medicalprocedure.

FIG. 4B illustrates the clip 400 in an expanded or second position (theclosed position may correspond to a first position). FIG. 4B illustratesthat the prongs 408 extend from the portions 402 and 404 into aninterior 410 defined by the portions 402 and 404. The prongs 408 areillustrated as being placed on or extending from an interior edge 414 ofthe clip 400. The prongs 408 can be placed anywhere on the interior edge414 including at the fold 406. As described in more detail below, theprongs may also be configured to extend from the exterior edge 418 (asshown for example in FIG. 6B).

The arrangement of the prongs 408 can vary. For instance, the prongs 408can be arranged in groups on the interior edge 414. FIG. 4B illustratesthat the prongs 408 are arranged in two groups on opposite sides of theinterior edge 414. However, the prongs 408 can be arranged in othergroups and be placed symmetrically and or asymmetrically on the interioredge 414. The number of prongs 408 in each group can be the same ordifferent. The configuration of the prongs 408 may be selected accordingto a size of the opening and/or to control trauma to the vessel. Inaddition, the prongs 408 can be substantially straight, have one or morecurves along their length, have a varying width and/or thickness.

The prongs 408 can also vary according to shape. In some instances, theprongs 408 may have different shapes or lengths and may be oriented indifferent directions. Some of the prongs 408 may extend further into theinterior 410 than other of the prongs 408. Some of the prongs 408 may beconfigured to completely pierce the tissue. For instance, some of theprongs 408 may be configured to engage a vessel wall by piercing thevessel wall. By engaging the vessel wall, the prongs 408 enable the clip400 to close the opening in the vessel.

In another example, some of the prongs 408 may only partially pierce thevessel wall. The prongs 408 may have different widths and/or lengths.The prongs 408 may have different or the same thicknesses. In addition,deformation or expansion of the clip 400 can change the direction inwhich the prongs 408 are oriented. In other words, the prongs 408 may beflexible in order to accommodate changes in the orientation or positionof the clip 400. Barbs 412 may also be located on at least some of theprongs 408. The barbs 412 are typically oriented to prevent the clip 400from detaching from the vessel wall. The barbs 412 are positioned toallow insertion of the prongs 408 into the vessel walls while resistingextraction of the prongs 408 from the vessel's walls. In other examples,prongs 408 may be excluded and/or replaced by another engagementmechanism. In some examples, a single prong (or more) may be oriented ina non-planar configuration and may have barbs that extend in differentdirections.

FIG. 4C illustrates a side view of the clip 400 in the closed position.FIG. 4C illustrates that the prongs 408 can extend from the portions 402and 404 in different ways. The prongs 408 may extend substantiallystraight or laterally from the portions 402 and/or 404. Alternatively,the prongs 408 may be angled relative to the portions 402, 404. In FIG.4C, the prongs 408 are directed towards the interior 410 but are alsoare angled away from the interior 410 in the closed position. FIG. 4Cillustrates that the prongs 408 may not extend straight from the edge414 (shown in FIGS. 4A-4B), but may extend at an angle from the edge414. The orientation of the prongs 408 may have an influence on how theclip 400 engages the tissue. The prongs 408 can be angled towards oraway from the opening in the tissue. In addition, the prongs 408 may becurved. For instance, the prongs 408 may begin curving away from theinterior 410 and then curve back towards the interior 410.

From a center of the clip, the body may be generally circular and have aradius of curvature. The radius of curvature can vary and be adapted toany potential deployment location.

FIG. 4D illustrates another example of a clip 450, which is an exampleof the clip 400. In the clip 450, prongs 454 originate from a body 452of the clip 450 and not necessarily from the edge 414. The prongs 454shown in FIG. 4D may have a gap between at least some of the prongs 454and the body 452 of the clip 400. The prongs 454 can extend from avariety of locations and in a variety of configurations. The prongs 454,like other embodiments disclosed herein, may be directed towards acenter of the clip 450 or more towards a side of the clip 450 or awayfrom the body of the clip 450.

FIG. 4E illustrates an example of the access device or clip 468 with alatch configuration. The latch configuration may include a first latch470 and/or a second latch 472. A single latch may be used. Theconfiguration of each latch is similar. In FIG. 4E, the latch 472extends from a portion (e.g., an outer edge) of the portion 404. Thelatch 472 has a tip 474 that is configured to extend towards a center ofthe clip 468 in the closed position. In an open position, the latch 472expends up when the body of the clip 468 is substantially flat. Thelatch 472 is flexible such that the latch 472 can be bent (and willreturn to its original shape from being bent) as necessary such that theouter edge of the portion 402 is held by the tip 474. The tip 474 may berounded such that when the clip 468 is closed, latch 472 can snap intoplace once the portion 402 moves towards the portion 404 and is past thetip 474. A rounded tip 474 enables the edge of the portion 402 to liftthe tip 474 until the outer edge passes the tip 474. At that point whenthe edge of the portion 402 passes the tip 474, the latch 472 returns toits original configuration and the clip 468 is held in a closedposition. Because the portions 402 and 404 are biased towards an openposition, lifting the tip allows the portions 402 and 404 to spread tothe open position automatically. The latch 472 may have a rounded bodythat extends from an outer edge of one portion 404 and curves toward theother portion 402. The latch 470 may be similarly configured.

FIGS. 5A and 5B illustrate the clip 400 deployed in a body lumen, suchas a blood vessel 100. FIG. 5A illustrates the clip 400 in the closedposition. In the closed position, the prongs 408 at least partiallyengage the walls of the vessel 100. The opening 102 in the vessel 100can be held at least partially closed by the clip 400. As previouslystated, the clip 400 may be partially expanded when attached to thevessel 100. This enables the prongs 408 to engage the vessel wall andpull the wall around the opening together. Alternatively, the clip 400can be pressed such that the prongs 408 engage the vessel wall.Alternatively, the clip 400 can engage the vessel 100 without beingpartially expanded. As the clip 400 is expanded, the prongs 408 turntowards the opening 102 in the vessel 100. This enables the clip 400 tomore firmly engage the vessel 100 in an expanded position.

FIG. 5B illustrates the clip 400 in the expanded position. To reach theexpanded position, the portions 402 and 404 are generally pushed awayfrom each other. The direction in which the portions 402 and 404 arepushed can depend on the relative orientation of the portions 402 and404. In one example, both the open and closed positions may be insubstantially in the same plane. Alternatively, the clip 400 may deformat least at the fold 406 to enlarge the interior 410. As a result,pushing the portions 402 and 404 away from each other tends to unfoldthe body of the clip. In the expanded position, the prongs 408 continueto hold the vessel walls and allow the introduction of medical devices.As indicated above, the prongs 408 turn inward towards the openingduring expansion of the clip 400. The clip 400 can be expanded merely bythe introduction of a medical device. In other words, the medical deviceitself may serve as an expander for the clip 400. The clip 400 does notsignificantly impede the introduction of the medical device. At the sametime, the clip 400 can prevent or reduce tearing in the opening.

Further, the prongs 408 are typically positioned such that they do notimpede withdrawal of any medical devices. This can be achieved bycontrolling a length of the prongs 408, selecting a placement of theprongs 408 on the interior and/or exterior edges 414 and 418 of the clip400, the orientation of the prongs (towards the center of the clip, awayfrom the clip), and the like. For instance, the portions 402 and 404 mayeach have two prongs that are laterally spaced or placed closer to thefold 406. Placing the prongs near the fold 406 leaves the interior 410of the clip 400 substantially free of prongs to enable the introductionof medical devices while still allowing the clip 400 to engage thevessel and protect the vessel from future trauma.

FIG. 6A shows an illustrative example of another embodiment of a clip600 in an open or expanded position. The clip 600 may be an example ofother clips or access management devices discussed herein. FIG. 6A showsthe clip in an open or expanded position. FIG. 6B shows the clip 600 ina closed position. FIGS. 6A and 6B illustrate the clip 600 deployed atan opening 102 in a vessel 100. The clip 600 includes a portion 602 anda portion 604 that may be similar to the portions 402 and 404 describedherein. The clip 600 also includes prongs 606, in this example, that arelocated on or extend from a bottom or an outer edge 612 of the clip 600and which are embedded in a wall of the vessel 100. More specifically,the prongs 606 may appear to extend from a bottom of the clip 600 in theopen position illustrated in FIG. 6A. An orientation of the edge 612changes as the clip 600 moves between the open and closed positions. Theprongs 606 on the portion 602, in the closed position, may be angledtoward the prongs 606 on the portion 604. Alternatively, the prongs maybe angled away from the opening 102.

During deployment of the clip 600, the clip 600 may be expanded,although expansion during deployment is not required. In deploying theclip 600, the prongs 606 engage the walls of the vessel 100 and the clipis in closed position as shown in FIG. 6B. In fact, the clip 600 can bedeployed in the closed position. In one example the vessel is split oropened after the clip 600 (or other clip illustrated herein) is deployedin the closed position. Thus, the vessel can be split or opened to formthe opening 102 when the clip is in the closed position as shown in FIG.6B in one example. The clip 600 can keep the opening 102 substantiallyclosed even after the opening 102 is formed. The clip 600 can then beexpanded to the open position as illustrated in FIG. 6A. Insertion of adevice, by way of example, may open or expand the clip 600 to the openposition illustrated in FIG. 6A. After the device is withdrawn or whenthe clip 600 is released, the portions 602 and 604 contract towards eachother to generally close the opening 102 by bringing the walls of thevessel together as the portions 602 and 604 move towards each other toclose the opening 102. In this example, the prongs 606 on the portion602 are embedded on one side of the opening 102 and the prongs 606 onthe portion 604 are embedded on a different side of the opening 102. Asa result, opening and closing the clip 600 can open and close theopening 102. This enables access to the lumen of the vessel 100 to becontrolled. For example, the clip 600 can be expanded to allow theintroduction of other medical devices through the interior area 608defined by the clip 600 when in the open position. And the clip 600 canbe closed as necessary. The clip 600 can be opened manually without adevice being inserted or closed manually. Alternatively, insertion of adevice through the clip 600 may open the clip 600 and withdrawal of thedevice may automatically result in the clip 600 contracting to close theopening 102.

The prongs 606 are oriented to engage the wall of the vessel 100 aroundthe opening 102. The prongs 606 on the portion 602 may be angled towardsthe prongs 606 on the portion 604 of the clip 600.

In one example of the clip 600, the clip 600 may have a memory such thatthe unbiased position of the clip 600 is closed, as illustrated in FIG.6B. However, the clip 600 may alternatively be configured to be bi-modalsuch that the clip 600 can remain closed without any external bias andthe clip 600 can also remain open without any external bias. In thisexample, the portion 602 and/or the portion 604 may flex in a mannerthat causes the clip 600 to remain in the open position.

The portions 602 and/or 604 may be configured such that as the clip 600moves from one position (e.g., closed) to another position (e.g., open),the portions may begin to bend or deform. At a certain point in thedeformation, the portions snap or become biased towards the otherposition. Thus, the clip 600 becomes bi-modal and can remain stable ineither the open or closed position.

FIGS. 7A-7B illustrate another embodiment of an access device or cliphaving a body 700 in closed position and an open position. FIG. 7Aillustrates the clip 700 in a closed position and FIG. 7B illustratesthe clip in an open position. The clip 700 may be configured to have adiamond, square, or rectangular orientation or shape. The clip 700,however, may also have a circular or ellipsoidal shape or orientation orother shape.

The clip 700 may include a bar 706 that cooperates with a latch 704 tobias the clip 700 in a closed position as shown in FIG. 7A. The bar 706connects with or extends from the body of the clip 700, at a corner 708for example or from another location on the body of the clip 700. Thebar 706 may be an integral part of the body of the clip 700.

The bar 706 and the clip 700 are configured such that movement of thebar 706 towards the latch 704 applies a bias to the body of the clip 700and causes the corners 708 and 714, or more generally, the sides of theclip to move towards each other. The movement may occur in more than onedimension. For example, as the sides of the clip move towards eachother, the ends 718 may move in another direction (e.g., up or down orperpendicularly to the movement of the sides of the clip 700. Theportions of the clip can thus be reoriented in a direction along alongitudinal axis of the vessel, in a circumferential direction aroundthe vessel 100, transverse to the longitudinal axis of the vessel 100,or any combination thereof.

Movement of the bar 706 can flex the clip 700 such that the sides orcorners 708 and 714 move in the direction 720 and/or the direction 722.Further, the clip 700 may have a curved shape 724. Because the clip 700may include prongs in an example (similar to prongs described herein andlocated on an exterior side and/or an interior side or edge of theclip), the opening 102 is closed when the clip 700 is moved to theclosed position. As a result, the clip 700 in the open position shown inFIG. 7B may have a planar shape and closure of the clip 700 may providea curvature 724 (see FIG. 7A) to the body as the sides are drawn intowards each other in one or more directions (e.g., directions 720 and722).

The bar 706 may be operative to bias the clip 700 in a closed position.The bar 706 can be operated (moved) to transition or bias the clip 700to the closed position. For example, pushing on the bar 706 in aparticular direction can apply a biasing force that moves the clip 700to the closed position. When the biasing force is removed, the clip 700returns to its original shape. In the closed position, a width 710 ofthe clip 700 is smaller than a width 712 in an open position as shown inFIG. 7B.

The clip 700 shown in FIG. 7B may have a planar or substantially planarshape such that the clip 700 can lie flat against a surface of thevessel 100. Alternatively, the clip in the closed position may have somecurvature and the surface of the vessel may adapt to the shape of theclip 700. When the bar 706 is moved inwards, the planar shape or curvedshape may deform to become more curved as illustrated in FIG. 7A.

The opening 102, for example, may be pinched closed by a change in theshape of the clip 700 when moving to the closed position. The bar 706can then removably engage with the latch 704 to hold the clip in theclosed position, which can close the opening 102 in the vessel 100. Thelatch 704 may be a curved hook, or other structure configured to atleast temporarily hold the bar 706. Because the clip 700 is anchored tothe vessel 100 as disclosed herein, the latch 704 can cooperate with thebar 706 to keep the clip 700 in the closed position. When the bar 706 isunlatched or uncoupled or disconnected from the latch 704, the clip 700returns to an unbiased or open position shown in FIG. 7B.

In another example, the clip 700 may not include the bar 706 or thelatch 704. In this example, the clip is configured to have an inflectionpoint that can be used to move the clip 700 between two positions (e.g.,the open and closed positions). The sides of the clip 700 may beconfigured such that when the ends 702 and 718 are bent, the clip 700passes the inflection point and snaps to the open position.

The clip 700 can be adjusted from the closed position to the openposition by pushing in one direction on the ends 702 and 718 while themiddle of the clip 700 is biased or pushed in the other direction.Similarly, adjusting the clip 700 from the open position to the closedposition can be achieved by pushing on the ends 702 and 718 while aforce is applied to the middle of the clip 700. The direction of theforces depends on the current position of the clip. In this example,once the clip (starting from one position) is pushed or forced past aninflection point, the clip is configured to snap to the other position.

FIGS. 8A-8B illustrate another example of a bi-modal clip. FIG. 8Aillustrates a clip 800 in a closed position and FIG. 8B illustrates theclip 800 in an open position. A clip 800 includes a body having a firstportion 802 and a second portion 804. The first portion 802 is attachedto the second portion at attachment points 806 and 808. The portion 802and the portion 804 can, however, be formed as a single integral body.

In one example, the portion 802 may have a thicker and/or stiffer bodyand the portion 804. As a result, the portion 804 can flex between theclosed position shown in FIG. 8A to the open position shown in FIG. 8B.The portion 804 can bend towards the portion 802 to keep the opening 102substantially closed.

More specifically, the portion 804 is configured to have a length thatis longer than a distance between ends 806 and 808. As a result, theportion 804 can be bent in towards the portion 802 to close the opening102. The portion 804 can then be pushed away from the portion 802.During this transition to the open position, the portion 804 may deformin order to accommodate the transition. At a certain point of thetransition, spring of the portion 804 pushes the portion 804 away fromthe opening 102 and/or the portion 802, which opens the opening.

The portion 804 may not plastically deform. However, the portion 804 canbe biased in the closed position shown in FIG. 8A and biased in the openposition shown in FIG. 8B. No external force (e.g., the insertion of amedical device) is required to keep the clip 800 in the open position orthe closed position. In one example, the portion 804 is less stiff thanthe portion 802. The flexibility of the portion 804 enables it to bemoved from the closed position to the open position. The portion 804 hasa length that is longer than a distance between ends of the portion 802to which the portion 804 is attached. As a result, the portion 802 iscurved outwardly in the open position and inwardly in the closedposition. The curve in the portion 802, whether inwardly or outwardlyoriented, prevents the portion 802 from transitioning from the closedposition to the open position or vice versa without an external force.

Both portions 802 and 804 may have prongs that embed in the vessel. As aresult, opening and closing the clip 800 opens and closes the opening102 since the clip 800 is attached to the vessel walls surrounding theopening.

In one example, the portion 802 has a body shaped to surround (e.g., “U”shaped) the opening 102 at least partially. The portion 802, aspreviously stated, may be less subject to deforming to enable theportion 804 to snap between the open and close positions. The portions802 and 804 may also have substantially the same length such that, whenthe clip 800 is in the closed position, the portions 802 and 804 areclose and may be in contact with each other. In this manner, the opening102 can be closed or substantially closed by the clip 800. The portionsmay, in some embodiments, have different lengths.

The bi-modal clip illustrated in FIGS. 8A-8B illustrated can maintainmore than one position. The clip 800 can control access to tissue byopening the opening 102 when desired and by closing the opening 102 whendesired. In one example, the portions 802 and 804 stay in substantiallythe same planar orientation when transitioning from one position toanother. Even if the body of the clip 800 is curved to accommodate asurface of the vessel, the movement of the portion 804 relative to theportion 802 occurs laterally in one embodiment. However, the bimodalityof the clip 800 can occur in more than one direction or dimension.

The portions 802 and 804 (as well as portions of other clips discussedherein) may be formed of the same or of different materials Examplematerials include, but are not limited to, stainless steel, titanium,nitinol, elgiloy or other suitable materials, or combinations thereofsome of which may have a memory effect. More generally, these materialsmay be included in other embodiments disclosed herein.

FIGS. 9A-9C illustrate another example of a bi-modal clip. A clip 900includes a portion 902 and a portion 904. The portions 902 and 904 mayeach have approximately half of the clip's body, but other proportionsmay be possible. The clip 900 has a body that is formed from a singleintegral loop. The loop 902 is separated from the portion 904 atlocations 906 and 908. The body of the clip 900 is twisted such that theportion 904 is oriented at an angle with respect to the portion 902.

In one example, a thickness and a width of the portion 902 may besubstantially the same as a thickness and a width of the portion 904.However, the portion 904 is twisted or rotated with respect to theportion 902.

FIG. 9B illustrates a top view of the clip 900 in an open position andFIG. 9C illustrates the clip 90 is a closed position. The clip 900 mayengage a vessel or tissue surrounding an opening as described herein.Thus, both the portion 902 and the portion 904 may have an engagementmechanism, such as prongs, that are configured to engage with the tissueto keep the clip 900 removably attached to the vessel or tissue.

Because the portion 904 is rotated or twisted with respect to theportion 902, the portion 904 can be moved between open positionillustrated in FIG. 9B and the closed position illustrated in FIG. 9C.The portion 904 of the clip 900 can move in directions shown by thearrow 910. Advantageously, the clip 900 is configured such that the clip900 can self-maintain the open position and the closed position.

More specifically, a spring force of the portion 904 keeps the clip 900in the open position. The portion 904, because it is twisted, isflexible in the directions of the arrow 910. The portion 902, incontrast, is much less flexible in the directions of the arrow 910.However, as the portion 904 moves between the open position and theclosed position, ends of the portion 902 may flex outwardly to assistthe portion 904 in transitioning from the open position to the closedposition and vice versa.

When the potion 904 is pushed towards the portion 902, the middle bendsinwardly. At a certain point, the portion 904 reaches a transition pointand snaps to the closed position shown in FIG. 9C. The ends of theportion 902 may exert an inward force at the locations 906 and 908 tokeep the clip in the closed position.

When the portions 902 and 904 are connected or engaged with tissue andan opening is located inside the clip 900, moving the clip 900 asdescribed herein manage access to the tissue by opening and/or closingthe opening in the tissue. The clip 900 may exert pressure on theopening such that the opening can be held closed and no further closuremechanism (e.g., sutures or a closure element) is needed to permanentlyclose the opening.

FIG. 9A illustrates that the locations 906 and 908 are twisted. Thematerial can be formed in this position or heat set in this position.The clip 900 may be formed of Nitinol or other material that iselastically deformable.

Together, the portions 902 and 904 are circular in shape or ellipticalin shape, although other shapes are possible. In one example, theportion 902 is generally “U” shaped with sufficient radius toaccommodate and allow the portion 904 to move between the positionsillustrated in FIGS. 9B and 9C. In this example, the width of theportion 902 is oriented in the same direction as the thickness of theportion 904. The difference in dimension helps keep the clip 900oriented. In one example, this orientation ensures that the portion 904can flex relative to the portion 902 while the portion 902 remainssubstantially stationary (even though it may move in a directionorthogonal to the arrow 910 when flexing or moving between the open andclosed position.

In one example, the portions may be similarly configured and havesimilar stiffness. However, the orientation of the portion 902 to theportion 904 enables the portion 904 to be more flexible compared to theportion 902. Thus, the portion 904 can be used bi-modally to controlaccess to tissue.

The clips 800 and 900, like other embodiments disclosed herein, may alsoinclude prongs extending from a body or from an edge of the body asappropriate such that the clip 800 and 900 can be attached to tissue. Insome examples, the prongs of one portion (e.g., the portion 902) mayextend from a body while the prongs of another portion (e.g., portion904) of the clip 900 may extend from an edge of the body.

FIG. 10A illustrates a perspective view of another example of a bi-modalclip. A clip 1000 include a portion 1006 and a portion 1008 ends 1010and 1012 are connected by a connector 1002, which may be circular,elliptical or another shape. The other ends of the portions 1006 and1008 are similarly connected. The connector 1002 connects to theportions 1006 and 1008 at a location above the ends 1010 and 1012 suchthat the ends 1010 and 1012 extend into a middle portion of theconnector 1002.

The connector 1002 is configured to allow the portions 1006 and 1008 tobe moved away from each other and towards each other. The connector 1002ensures that the portions are automatically kept in either the openposition or the closed position. The portions 1006 and 1008 may alsohave prongs extending therefrom in order to engage tissue. As describedherein with respect to other examples of the clip, the clip 1000 canthus be used to manage access to tissue and keep an opening in thetissue either open or closed.

FIG. 10B illustrates the clip 1000 in the closed position andillustrates the positions of the portions 1006 and 1008 relative to theconnector 1002. In one example, the ends 1022 and 1024 of the connector1002 can push against or near the ends 1010 and 1012. Because the ends1010 and 1012 extend into a middle portion of the connector 1002, theportions 1006 and 1008 cannot be inadvertently separated sinceseparation causes the ends 1010 and 1012 to push against each other.

FIG. 10C illustrates the clip 1000 in the open position. In thisexample, the portions 1006 and 1008 are pushed away from each other. Theends 1010 and 1012 may be bent substantially flat or such that the ends1010 and 1012 exert a force to keep the portions 1006 and 1008 away fromeach other. In the open position, the connector 1002 is expanded and mayexert a force pushing the ends 1010 and 1012 towards each other. Theends 1010 and 1012, combined with the force exerted by the connector1002 keep the clip 1000 in an open position. The ends 1010 and 1012 mayinclude, respectively, flat portions 1026 and 1028 that are configuredto abut against each other at least partially in the open position. Byforming flat portions (or angled portions), the ends 1010 and 1012provide a more stable surface and enable the clip to open to aparticular orientation. In other words, as the clip moves to the openpositions, the flat portions 1026 and 1028 may eventually abut againsteach other and allows the portions 1006 and 1008 to push against a flatsurface, which can help the clip maintain the open position easier thanif the ends are curved. The flat portions 1026 and 1028 may be locatedat different locations on the ends 1010 and 1012 (even though therelative placement may be the same in some examples) and may be placedon the ends 1010 and 1012 to cause the portions 1006 and 1008 to form anangle less than, equal to, or greater than 180 degrees in the openposition (FIG. 10C illustrates that the portions 1008 and 1006 form anangle of about 180 degrees). In some examples, the open position ismaintained without flat portions.

FIG. 10D illustrates the clip transitioning from the open position tothe closed position or vice versa. When the portions 1006 and 1008 areseparated, for example, by a user, a resistive force is encountered bythe ends 1010 and 1012 pushing against each other. As the portions 1006and 1008 continued to be pushed apart, the connector 1002 begins to opento allow the ends 1010 and 1012 and more particularly the portions 1006and 1008 to be separated. At a particular point, the clip 1000 snaps tothe open position as the ends 1010 and 1012 reach a point where theconnector 1002 can begin to close. Thus, the connector 1002 continues topush the portions 1006 and 1008 apart, but further separation issubstantially prevented by the tissue in which the clip 1000 is engaged.The ends 1010 and 1012 may also have various geometries to hold the clipin the open position. For example, the ends 1010 and 1012 may have aflat portion or an angled portion that are configured to abut againsteach other when the clip is opened. This enables the clip itself to bearmost of the force rather than the tissue. As a result, the force on thetissue is reduced or minimized, which reduces or minimizes trauma to thetissue.

Similarly, when the clip 1000 transitions from the open position to theclosed position, the portions 1006 and 1008 can be lifted or movedtowards each other. A resistive force is again encountered as themovement of the portions 1006 and 1008 towards each other cause theconnector 1002 to expand. At a certain point when the ends 1010 and 1012are in a certain position moving toward the middle portion of theconnector 1012, the resistive force is overcome and the ring 1002 canclose the clip 1000.

The connector 1002 of the clip 1000 is configured to allow the ends 1010and 1012 to be arranged in a manner that allows the clip to stay in anopen position. The connector 1002 may have a generally circular orelliptical shape that is open where the connector 1002 attaches to theends 1010 and 1012. In this example, the ends 1010 and 1012 extend intoa middle portion of the connector 1002. When the clip 1000 is opened,the ends 1010 and 1012 interfere or press against each other in themiddle portion of the connector 1002. This causes the connector 1002 toexpand. At a certain point, the ends 1010 and 1012 reach a positionwhere the clip is effectively pushed to the open position as the ends1010 and 1012 push against each other. When the ends 1010 and 1012 havea flat portion, these flat portions then abut against each other andprovide stability to the clip and may keep the clip in a particularorientation.

FIGS. 10A-10D thus illustrate that the clip 1000 is a bi-modal clip thatcan be moved to either an open or closed position. The clip 1000 isconfigured such that the ends 1010 and 1012 of the portions 1006 and1008 cooperate to bias the clip 1000 bi-modally to be held, without anyother bias, in the open position or in the closed position.

In one example, the connector 1002 is an integral part of the portions1006 and 1008. The clip 1000 may be formed of any suitable material,including a memory material. Even if the bi-modal clip is formed of amemory material, the ends 1010 and 1012 may cooperate with the connector1002 to keep the clip 1000 in a given position due to the biasing forcesdescribed herein.

Embodiments relate to clips configured to exhibit stability in twopositions (e.g., an open or expanded position and a closed or unexpandedposition). This bi-modality enables the clip to hold an opening closedor open according to need. As illustrated and discussed herein, bi-modalclips can be achieved using different configurations. Bi-modal clips canself-maintain in open or closed positions. At least some embodiments ofthe clips disclosed herein can be stable and maintain an open or closedposition without an external force.

The bi-modality of clips is exemplarily illustrated when transitioningfrom one position to another. Because the clip can maintain eitherposition, a force is typically applied to transition to anotherposition. At a certain point of the transition, the shape of the clipcauses the forces holding the state stably to switch to the otherposition. The inflection point is the point where the forces acting onthe clip change to move the clip to the other position.

Some embodiments of the clips (e.g., the clip 468 in FIG. 4E and theclip 700 in FIGS. 7A-7B) may include a latch or a combination of a barand a latch. The latches used in these examples can exhibit a snapaction, a frictional or mechanical interaction that enables the clips tobe held in either a closed or an open position. For example, one portionof the clip may include a small protrusion that frictionally fits in acorresponding opening formed in the other portion of the clip. Thefrictional fit may keep the clip in the closed position.

In some examples, the natural or unstressed position of the clipsdisclosed herein may be somewhere between a closed position and an openor a fully open position. As a result, some latches can be configured tohold the clip in the open and/or the closed position. Further, the clipscan be deployed in various positions and can optimize tissue accesscontrol.

In one embodiment, a clip or clips of the present invention can includea material made from any of a variety of known suitable materials, suchas a shape memory material (SMM). SMMs have a shape memory effect inwhich they can be made to remember a particular shape. Once a shape hasbeen remembered, the SMM may be bent out of shape or deformed and thenreturned to its original shape by unloading from strain or heating.Typically, SMMs can be shape memory alloys (SMA) including metal alloys,or shape memory plastics (SMP) including polymers.

The main types of SMAs are as follows: copper-zinc-aluminum;copper-aluminum-nickel; nickel-titanium (NiTi) alloys known as nitinol;and cobalt-chromium-nickel alloys or cobalt-chromium-nickel-molybdenumalloys known as elgiloy alloys.

A shape memory plastic (SMP) can be fashioned into a clip in accordancewith the present invention. When an SMP encounters a temperature abovethe lowest melting point of the individual polymers, the blend makes atransition to a rubbery state. The elastic modulus can change more thantwo orders of magnitude across the transition temperature (Ttr). Assuch, an SMP can be formed into a desired shape of a clip by heating theclip above the Ttr, fixing the SMP into the new shape, and cooling thematerial below Ttr. The SMP can then be arranged into a temporary shapeby force, and then resume the memory shape once the force has beenremoved. Examples of SMPs include, but are not limited to, biodegradablepolymers, such as oligo(ε-caprolactone)diol, oligo(p-dioxanone)diol, andnon-biodegradable polymers such as, polynorborene, polyisoprene, styrenebutadiene, polyurethane-based materials, vinyl acetate-polyester-basedcompounds, and others yet to be determined. As such, any SMP can be usedin accordance with the present disclosure.

In one embodiment, the clip can include a variety of suitable deformablealloy metal materials, including stainless steel, silver, platinum,titanium, tantalum, palladium, cobalt-chromium alloys or other knownbiocompatible alloy metal materials.

In one embodiment, the clip can include a suitable biocompatible polymerin addition to or in place of a suitable metal. The clip can includebiodegradable or bioabsorbable materials, which can be elastically,plastically, or otherwise deformable or capable of being set in thedeployed configuration.

Moreover, the clip can include a radiopaque material to increasevisibility during placement. Optionally, the radiopaque material can bea layer or coating any portion of the clip. The radiopaque materials canbe platinum, tungsten, silver, stainless steel, gold, tantalum, bismuth,barium sulfate, or a similar material. The radiopaque material can beapplied as layers on selected surfaces of the stent using any of avariety of well-known techniques, including cladding, bonding, adhesion,fusion, deposition, or the like.

It is further contemplated that the external surface and/or internalsurface of the clip or clip element (e.g., exterior and/or interioredges or surfaces) can be coated with another material having acomposition different from a primary clip material. The use of adifferent material to coat the surfaces can be beneficial for impartingadditional properties to the clip, such as providing radiopaquecharacteristics, drug-reservoirs, and improved biocompatibility.

In one configuration, the external and/or internal surfaces of a clipcan be coated with a biocompatible polymeric material as describedherein. Such coatings can include hydrogels, hydrophilic and/orhydrophobic compounds, and polypeptides, proteins, amino acids, or thelike. Specific examples can include polyethylene glycols,polyvinylpyrrolidone (PVP), polyvinylalcohol (PVA), parylene, heparin,phosphorylcholine, polytetrafluorethylene (PTFE), or the like.

The coatings can also be provided on the clip to facilitate the loadingor delivery of beneficial agents or drugs, such as therapeutic agents,pharmaceuticals, and radiation therapies.

Accordingly, the coating material can contain a drug or beneficial agentto improve the use of the clip. Such drugs or beneficial agents caninclude antithrombotics, anticoagulants, antiplatelet agents,thrombolytics, antiproliferatives, anti-inflammatories, agents thatinhibit hyperplasia, inhibitors of smooth muscle proliferation,antibiotics, growth factor inhibitors, or cell adhesion inhibitors, aswell as antineoplastics, antimitotics, antifibrins, antioxidants, agentsthat promote endothelial cell recovery, antiallergic substances,radiopaque agents, viral vectors having beneficial genes, genes, siRNA,antisense compounds, oligionucleotides, cell permeation enhancers, andcombinations thereof.

Embodiments of the clip disclosed herein can be comprised of a varietyof known suitable materials (which may be deformable), includingstainless steel, silver, platinum, tantalum, palladium, nickel,titanium, nitinol, nitinol having tertiary materials, niobium-tantalumalloy optionally doped with a tertiary material, cobalt-chromium alloys,or other known biocompatible materials. Such biocompatible materials caninclude a suitable biocompatible polymer in addition to or in place of asuitable metal. A device or member can include biodegradable orbioabsorbable materials, which can be either plastically deformable orcapable of being set in the deployed configuration.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

What is claimed is:
 1. A clip for managing access to an opening intissue, the clip comprising: a body having an interior edge and anexterior edge, with an upper surface and a lower surface at oppositeends of each of the interior edge and the exterior edge, the body havinga first portion connected to a second portion at two fold junctions; thebody of the clip is configured to maintain both an open position and aclosed position, the body including at least one holding structure thatmaintains the body of the clip in the closed position, the at least oneholding structure extending from the body at a location remote from thetwo junctions and extending over the upper surface and around a portionof the exterior edge towards the lower surface; and an engagementmechanism extending from the body to attach to the tissue, the body isconfigured to deform from a first position to a second position whilethe engagement mechanism is attached to the tissue.
 2. The clip of claim1, wherein the engagement mechanism comprises at least one prong thatextends toward an interior of the body.
 3. The clip of claim 2, whereinthe at least one prong extends at an angle from the interior edge. 4.The clip of claim 2, the body including the first portion and the secondportion, wherein the first portion and the second portion are joined ata fold in the body at the two junctions.
 5. The clip of claim 4, whereinthe first portion and the second portion are arranged in a closedposition.
 6. The clip of claim 4, wherein the first portion and thesecond portion each have a curve to accommodate the tissue.
 7. The clipof claim 4, wherein the at least one prong includes a first group ofprongs extending from the first portion and a second group of prongsextending from the second portion.
 8. The clip of claim 2, wherein theat least one prong extends at an angle from the exterior edge.
 9. Theclip of claim 1, wherein the interior edge defines an interior sized toallow introduction of a medical device through the opening.
 10. A clipfor reducing trauma to an opening formed in tissue, the clip comprising:a monolithic body including a first portion, a second portion, and afold, the fold joining the first portion and the second portion, whereinthe first portion and the second portion are set in a first position andconfigured to deform to a second position, wherein the body is formed tomaintain self-bias in the two different positions without an externalbias with the first portion and the second portion of the body beinggenerally coplanar in an open position and the body having a foldedorientation in the second position, the open position being one of thetwo different positions and a closed position being another of the twodifferent positions; and a plurality of prongs extending from the firstportion and from the second portion, the plurality of prongs areconfigured to engage the tissue around the opening and attach the bodyto the tissue while the body is in both the first position and thesecond position.
 11. The clip of claim 10, further comprising barbsformed on at least some of the plurality of prongs.
 12. The clip ofclaim 10, wherein the plurality of prongs are adapted to move moretowards the opening as the body deforms from the first position to thesecond position.
 13. The clip of claim 10, wherein the first portion andthe second portion are defined by an interior edge and an exterior edge,wherein the interior edge defines an interior of the body.
 14. The clipof claim 13, wherein the plurality of prongs extend laterally from theinterior edge.
 15. The clip of claim 13, wherein the plurality of prongsextend at an angle from the interior edge.
 16. The clip of claim 13,wherein the plurality of prongs extend from the exterior edge laterallyor at an angle.
 17. The clip of claim 13, wherein the first portion andthe second portion are curved, wherein the first portion and the secondportion are arranged in a generally U-shaped configuration in the firstposition and wherein the first portion and the second portion aresubstantially flat in the second position.
 18. A clip for reducingtrauma to an opening formed in tissue, the clip comprising: a bodyincluding a first portion and a second portion forming a single integralloop, the first portion being orientated at an angle with respect to thesecond portion with a twisted portion between first ends of the firstportion and the second portion and second ends of the first portion andthe second portion, the twisted portion being twisted about an axisextending along a length of the body from the first portion to thesecond portion; and a plurality of prongs extending from the firstportion and from the second portion, the plurality of prongs configuredto engage the tissue around the opening and attach the body to thetissue; wherein the second portion has a length longer than a distancebetween the first and second ends of the first portion, wherein thesecond portion can maintain a first position to keep the opening closedand maintain a second position to keep the opening open; wherein thesecond portion can maintain the first position and the second positionwithout any external force, the second portion being received within aspace defined by an inner periphery of the first portion in the firstposition and extending away from the space defined by the first portionin the second position.
 19. A method for managing access to tissue, themethod comprising: forming an opening in the tissue; placing a clip onthe tissue, wherein the clip engages the tissue around the opening, theclip having a first portion and a second portion; and expanding the clipto a biased open position in order to introduce medical devices throughan interior defined by the clip and through the opening by moving thefirst portion from the second portion beyond a transition movement pointbeyond which the clip transitions from a biased closed position to thebiased open position, in the biased open position the first portion andthe second portion of the clip are generally coplanar, then moving thefirst portion and the second portion of the clip towards one anotherbeyond the transition point, wherein the clip transitions from thebiased open position to the biased closed position to substantiallyclose the opening; wherein the open position and the closed position ofthe clip each is maintained without an external bias.
 20. The method ofclaim 19, further comprising engaging the clip in the tissue, whereinthe clip comprises a plurality of prongs disposed on an interior edge ofthe clip or an exterior edge of the clip.
 21. The method of claim 19,wherein expanding the clip further comprises preventing the opening fromtearing beyond the interior of the clip.
 22. A clip for managing accessto tissue, the clip comprising: a first portion having a first free end,the first portion is configured to engage the tissue; a second portionhaving a second free end, the second portion is configured to engage thetissue, wherein the first portion and the second portion are movablebetween an open position and a closed position and are configured tomaintain a closed position and an open position; and a connector that isconfigured to connect the first portion to the second portion, theconnector encircling the first free end and the second free end as itextends from an outer surface of first portion to an outer surface ofthe second portion in the closed position of the clip, wherein theconnector is configured to cooperate with the first end and the secondend such that the first and second portions are maintained in the closedposition when pushed towards each other and such that the first andsecond portions are maintained in the open position when pushed awayfrom each other; wherein said first portion, second portion, andconnector are formed as a unitary structure.
 23. The clip of claim 22,wherein a transition of the first portion and the second portion betweenthe closed position and the open position reaches a transition pointsuch that forces keeping the first and second portions in the closedposition change to keep the first and second portions in the openposition.
 24. The clip of claim 22, wherein the first end and the secondend each include a flat portion, the flat portions configured to abutagainst each other when in the open position.